#ifndef LISTOP_H
#define LISTOP_H


#ifdef __cplusplus
extern "C"
#endif
      
    struct list_head {  
        struct list_head *next, *prev;  
    };  
      
    typedef struct list_head list_t;  
      
    #define LIST_HEAD_INIT(name) { &(name), &(name) }   
      
    #define LIST_HEAD(name) \   
        struct list_head name = LIST_HEAD_INIT(name)  
      
    #define INIT_LIST_HEAD(ptr) do { \   
        (ptr)->next = (ptr); (ptr)->prev = (ptr); \  
    } while (0)  
      
void list_add(struct list_head *pre, struct list_head *head);
      
    /**
     * list_add_tail - add a new entry
     * @new: new entry to be added
     * @head: list head to add it before
     *
     * Insert a new entry before the specified head.
     * This is useful for implementing queues.
     */
    void list_add_tail(struct list_head *pre, struct list_head *head);
      
      
    /** 
     * list_del - deletes entry from list. 
     * @entry: the element to delete from the list. 
     * Note: list_empty on entry does not return true after this, the entry is in an undefined state. 
     */  
    void list_del(struct list_head *entry);  
      
    /** 
     * list_del_init - deletes entry from list and reinitialize it. 
     * @entry: the element to delete from the list. 
     */  
    void list_del_init(struct list_head *entry);  
      
      
    /** 
     * list_move - delete from one list and add as another's head 
     * @list: the entry to move 
     * @head: the head that will precede our entry 
     */  
    void list_move(struct list_head *list, struct list_head *head);  
      
      
    /** 
     * list_move_tail - delete from one list and add as another's tail 
     * @list: the entry to move 
     * @head: the head that will follow our entry 
     */  
    void list_move_tail(struct list_head *list,  
                      struct list_head *head);  
      
    /** 
     * list_splice - join two lists 
     * @list: the new list to add. 
     * @head: the place to add it in the first list. 
     */  
    void list_splice(struct list_head *list, struct list_head *head);  
      
    /** 
     * list_empty - tests whether a list is empty 
     * @head: the list to test. 
     */  
    static int list_empty(struct list_head *head)  
    {  
        return head->next == head;  
    }  
      
    /** 
     * list_dequeue - dequeue the head of the list if there are more than one entry 
     * @list: the list to dequeue 
     */  
    struct list_head * list_dequeue( struct list_head *list );  
      
    /** 
     * list_entry - get the struct for this entry 
     * @ptr:    the &struct list_head pointer. 
     * @type:   the type of the struct this is embedded in. 
     * @member: the name of the list_struct within the struct. 
     */  
    #define list_entry(ptr, type, member) \   
        ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))  
      
    /** 
     * list_for_each    -   iterate over a list 
     * @pos:    the &struct list_head to use as a loop counter. 
     * @head:   the head for your list. 
     */  
    #define list_for_each(pos, head) \   
        for (pos = (head)->next; pos != (head); \  
                pos = pos->next)  
                  
    /** 
     * list_for_each_safe   -   iterate over a list safe against removal of list entry 
     * @pos:    the &struct list_head to use as a loop counter. 
     * @n:      another &struct list_head to use as temporary storage 
     * @head:   the head for your list. 
     */  
    #define list_for_each_safe(pos, n, head) \   
        for (pos = (head)->next, n = pos->next; pos != (head); \  
            pos = n, n = pos->next)  
      
    /** 
     * list_for_each_prev   -   iterate over a list in reverse order 
     * @pos:    the &struct list_head to use as a loop counter. 
     * @head:   the head for your list. 
     */  
    #define list_for_each_prev(pos, head) \   
        for (pos = (head)->prev; pos != (head); \  
                pos = pos->prev)  
                  
    /** 
     * list_for_each_entry  -   iterate over list of given type 
     * @pos:    the type * to use as a loop counter. 
     * @head:   the head for your list. 
     * @member: the name of the list_struct within the struct. 
     */  
    #define list_for_each_entry(pos, head, member)              \   
        for (pos = list_entry((head)->next, typeof(*pos), member);   \  
             &pos->member != (head);     \  
             pos = list_entry(pos->member.next, typeof(*pos), member))  
      
#endif


